First prototype
diff --git a/test.php b/test.php
new file mode 100644
index 0000000..10aed56
--- /dev/null
+++ b/test.php
@@ -0,0 +1,47 @@
+<?php
+/*require_once("core.php");
+
+$element = "Gtfs\CalendarDate";
+
+$item = new $element([
+ "service_id" => "a",
+ "date" => "b",
+ "exception_type" => Gtfs\CalendarDate\ExceptionType::ADDED
+]);
+
+//$feed->setServiceId(Gtfs\CalendarDate\ExceptionType::ADDED);
+
+var_dump(json_decode($item->serializeToJsonString(), true));
+*/
+?>
+
+<!DOCTYPE html>
+<html>
+ <head>
+ <style>
+ @media (orientation: landscape) {
+ :root {
+ --size: 4vh;
+ }
+ }
+
+ @media (orientation: portrait) {
+ :root {
+ --size: 4vw;
+ }
+ }
+
+ .a {
+ font-size: calc(4 * var(--size));
+ background: cyan;
+ width: 400px;
+ height: 400px;
+ }
+ </style>
+ </head>
+ <body>
+ <div class="a">
+ Adri
+ </div>
+ </body>
+</html>